Electric-arc lamp



(No Model.) 2 Sheets-Sheet 1.

W. B. LUCE.

ELECTRIC ARC LAMP.

No. 474,091. Patented May 3,1892.

MTA/[5555.

(No Model.) 2 Sheets-Sheet 2. W. B. LUCE.

ELECTRIC ARG LAMP.

No. 474,091. Patented May 3,1892.

@TA/5555.5. Wwf/V727 `UNTTED STATES WILLIAM B. LUCE, OF BROOKLINE, MASSACHUSETTS.

ELECTRIC-ARC LAMP.

SPECIFICATION forming part of Letter s Patent No. 474,091, dated May 3, 1892.

Application tiled August 8, 1891. Serial No. 402.080. (No model.)

To aM whom, t may concern.

Be it known that I, VILLIAM B. LUCE, of Brookline, in the county of Norfolk and State o f Massachusetts, have invented certain new and useful Improvements in Electric-Arc Lamps, of which the following is a specifican tion.

This invention relates to electric-arc lamps, and has for its object to improve and simplify the construction of the same. In electric-arc lamps as now commonly constructed and known to me two magnets are employed, one serving to lift the movable carbon to establish the arc and the other serving to control the action of a clutch mechanism by which one carbon, usually the positive carbon, is fed toward the other or negative carbon when the arc between the carbons becomes of abnormal size or length.

My invention has for its object to provide an electric-arc lamp in which a single magnet serves the double pu rpose of a lifting-magnet and a feed-magnet, and I accomplish my object by means of a solenoid provided with a magnetic core, having secured to or forming part of it a clutch, preferably constructed as will be described.

The particular features of the invention will be pointed out in the claims at the end of this specification.

Of the accompanying drawings, forming a part of this specification, Figure l represents in section and elevation a su'iiicient portion of of the arc lamp embodying my invention to enableit t be understood. Fig. 2 is an elevation of a detail showing the clutch shown in Fig. l in its normal or inoperative position. Fig. 3 represents a longitudinal section of the clutch shown in Fig. 2. Figs. A and 5 represent details in section of a modified form of clutch. Figs. 6 and 7 represent details hereinafter referred to. Fig. 8 represents a dia grammatic View of the lamp, a regulator, and a cut-out therefor.

Referring to Fig. l, a solenoid A of any well-known or usual construction is shown as provided with a tubular extension a. The

solenoid A is provided at its opposite ends with suitable guides CL2 a3, through which is extended the usual carbon-holding tube a4, having secured to it, as by set-screw a5, one carbon electrode or pencil a, which may be the positive carbon, and which cooperates with the negative-carbon electrode or pencil al, secured in the lamp in any usual or wellknown manner.

The solenoid A is provided with a magnetic core, which may be made in the form shown in Figs. 1, 2, and 3, or as shown in Figs. 3 to 7. Referring to Figs. 2 and 3, the magnetic core is made tubular in form, and consists of an upper semi-cylindrical portion d20, lower semi-cylindrical portion am, cross or connecting pieces or portions @22, rings C623 ai, rigidly fastened, as by screws c C026, to the said upper and lower portions, a movable ring C027, pivoted to the cross-pieces (L22, and an upper piece CLES and lower piece C029, fastened to the movable ring as by screws e am.

In practice, the carbonholding rod a is extended through the rings @23 a2" a2?, and when the current is cut off from the lamp the said rings are in line with each other and occupy the normal position shown in Figs. l, 2, and 3, the said rings at such time loosely encircling` the carbon-holder a4.

Vhen the current is supplied to the lamp, the solenoid A attracts the magnetic core within it, and the parts or portions t28 @29 of the magnetic core, being pivotally connected through the ring @27, are free to move under magnetic influence toward the walls of the solenoid, thereby turning the ring L27 on its pivot and causing the carbon-holding tube a4 to be forced against the diametrically-opposite side of the cutch-rings L23 am and thus securely clamp it (the said tube) to the magnetic core, so that as the magnetic core is moved within its solenoid the carbon a is drawn away from the carbon aT and the arc established. The current passingthrough the solenoid A acts to polarize the parts d20 @2S am a2 of the core, and like poles in the two parts being adjacent the parts are repelled, which action moves the parts tds Q29 in opposite directions.

The magnetic core is drawn up within its solenoid until the strength of the current passing through the solenoid is diminished by the formation of the arc to such extent as to attract the said magnetic core with less force, thus maintaining the are between the carbons at the desired or normal size or length.

As the are between the carbons becomes ab- IOO normal by the consumption of the same, the strength of the current passing through the lamp is diminished by the resistance interposed in the line by the abnormal arc and the weight of the carbon and its holder overcomes the attractive torce of the solenoid for its magnetic core, and the force with which the carbon-holder is gripped by the clutchrings is weakened sutliciently to permit the carbon a to feed toward the negative carbon a7 and restore the arc to its normal size or length. It will thus be seen that the feed of the carbon ab' toward its co-operating carbon a7 is controlled by the strength oi' the current passing through the solenoid A, and in practice the magnetic clutch is so sensitive to the strength of the current that the carbon a is almost continuously being fed toward itslower carbon a7, and as a result the are between the carbons is maintained at a substantially constant size, thereby giving a steadier and more brilliant light.

I may prefer to employ a magnetic core constructed as shown in Figs. l, 2, and 3; but I do not desire to limit myself in this respect, as the said magnetic core and clutch may be made in other forms-for instance, as shown in Figs. 4 to 7, inclusive, wherein the magnetic core is shown as composed of two semicylindrical pieces or shells t t', having secured to or forming part of them clutch-rings b2 b3. Two rings b3 are shown as secured to the shell h and one ring h2 to the shell i), the ring h2 being extended between the rings when in operative position.

Fig. 4 shows the magnetic core and clutch in the normal position, and Fig. 5 shows the said core and clutch in operative position.

My improved lamp may be provided with any usual or well-known form ot regulator and cut-out. The regulator, as represented in Fig. S, consists of ahigh-resistance solenoidf, having its coref attached to a lever f2, forming part of the main circuit through the lamp, the said lever being connected by wire 3 to the solenoid A, the other wire 4 of the solenoid being joined to the positive electrode d. lhe lever f co-operates with a series of contacts f 3, to which resistancesf1 are connected, the main-line wire 2 being joined to the lowest contact-plate f3, as herein shown. The lamp is provided with the usual binding-posts, (represented by flo fl) and the wires 7 S of this high-resistance magnet or solenoid f are Connected to the said binding posts. The

negative carbon ai is connected by wire 5 to the negative binding-post j, and the said wire includes in it a cut-out magnet t', controlling a normally-open shunt for the solenoid A, the said magnet having an armature 71 connected by wire 9 to the wire 3, and co-operating with a contact or terminal g', to which is connected one end of a resistance g', having its other end connected to the negative binding-post f1?.

Vhen the lamp 'is in operation, the magnet attracts its armature 7L and opens the shunt containing the resistance g; but it the lamp should become inoperative, as by reason of a broken carbon, the spring 7L would withdraw the said armature into contact with the terminal g and close the shunt-circuit around the solenoid A. The current coming in over the wire to the binding-postf10 flows over the wire 2, through one of the contact-pieces f2, arm f', wire 3, to the solenoid A, thence by wire 4 to the carbon d, thence to the carbon a7, wire 5, through the magnet 1', and to the negative post f1?, and out over the line-wire. A derived current, acting` through the solenoid f on the regulator-arm f', regulates the current passing through said arm to the lamp in the usual well-known manner.

The frame-work of the lamp is not herein shown, as it forms no part of my invention, and it may be of any desired or usual construction.

I claiml. In an electric-arclamp,the combination, with a movable carbon, of a solenoid and a magnetic core composed of two or more parts, and aclutch consisting ot clamping-rings secured to said parts and embracing the movable carbon, the said clamping-rings normally encircling the said carbon loosely and acting upon opposite sides oi' the said carbon to grip the same when the magnetic core is attracted by the solenoid, substantially as described.

2. In an electric-arc lamp, the combination, with a movable carbon, ot a solenoid, a magnetic core composed of two semi-cylindrical parts or halves, and one or more clampingrings secured to the inner side of each otf the said parts or halves, and through which thc movable carbon is extended, substantially as described.

3. In an electric-arc iamp, the combination, with a movable carbon, of a solenoid, a inagnetic core composed ot two semi-cylindrical parts C020 am and cross -piece @22, clamping- IOO rings @23 C021, attached to the said parts, a

clamping-ring @'27, pivoted to the cross-piece @'22, and pieces (L23 d20, attached to said pivoted ring, substantially as described.

In testimony whereof I have signed my name to this specification, in the presence ot two subscribing witnesses,this 5th day ot August, A. D. 1891.

VILLIAH B. LUCE.

Witnesses:

C. F. BnowN, EwINd W. HAMLEN. 

